Study of patients with intravenous contrast extravasation on CT studies, with radiology staff and ward staff cannulations.

INTRODUCTION: Intravenous (IV) contrast extravasation is an adverse outcome of computed tomography (CT) studies. This study evaluates for any differences in rates of extravasation between radiology (radiographer) staff and ward medical staff cannulations, and secondarily by cannula size and study type. METHOD: A prospective study of 26,854 studies in adults between September 2004 and April 2008 accumulated 119 extravasations. Patients were divided into two groups, those cannulated by radiology staff and those cannulated by non-radiology staff. Patients with extravasations were followed for treatment outcomes. Statistical analysis between our groups was undertaken. RESULTS: The total extravasation rate was 0.44%. The extravasation rate for those patients cannulated by radiology staff was 0.34% (n= 11,470 cannulations) and those cannulated by non-radiology staff was 0.52% (n = 15,384 cannulations). This was not statistically significantly different. The site where most extravasations occurred was at the elbow (71.4%). The injection rate where most extravasations occurred was in the 1-2 mL/s range (42%). No patient required surgical intervention or had any significant morbidity. CONCLUSION: Radiology radiographer staff can provide safe administration of IV contrast in CT scanning with low rates of extravasation. Extravasation may occur with high or low injection rates and when small or large size cannulas are used.

Prospective evaluation of selected clinical criteria for cranial computed tomography in non-trauma adult patients.

OBJECTIVE: To evaluate the usefulness of previously published criteria by Rothrock et al. and Harris et al. for urgent, cranial CT in non-trauma presentations. METHODS: A prospective, observational study of consecutive adult patients with non-trauma presentations to Westmead Emergency Department, undergoing urgent cranial CT over a period of 2 years and 10 months. Clinical data were assessed to determine the presence of the proposed Rothrock and Harris criteria. Clinically significant findings defined by CT were intracerebral haemorrhage, acute infarction, intracranial infection, acute hydrocephalus, cerebral oedema and malignancy. RESULTS: A total of 1911 patients were studied. Among them, 21.7% (414/1911) of patients had clinically significant findings on CT. Application of the Harris criteria demonstrated a sensitivity of 93.5% (387/414, 95% CI 90.7-95.7) and a false negative rate of 6.5% (27/414, 95% CI 4.3-9.3) with a potential reduction in number of scans by 27.8%. With application of the Rothrock criteria, the possible scan reduction rate was 15% with a sensitivity of 98.8% (409/414, 95% CI 97.2-99.6) and a false negative rate of 1.2% (5/414, 95% CI 0.4-2.8). CONCLUSION: The Harris criteria were not validated by our study. The Rothrock criteria are also not confidently validated, but can be a useful guide for emergency physicians to help prioritize high-risk patients who might have clinically significant cranial CT findings. We have not replicated their very high sensitivity and very low false negative rates.